Cardiovascular System: The Blood

Blood is 55% plasma and 45% formed elements.

The liquid component of blood, primarily water (91.5%), containing dissolved solutes.

The cellular components of blood, including red blood cells, white blood cells, and platelets.

Erythrocytes; responsible for oxygen transport.

Leukocytes; important for immunity and fighting infection.

Thrombocytes; crucial for blood clotting.

Blood carries oxygen, nutrients, hormones, and waste products.

Blood helps maintain pH, temperature, and water balance.

The percentage of total blood volume occupied by red blood cells.

A condition caused by a significant drop in hematocrit, signifying a lower than normal number of red blood cells (RBCs).

A condition characterized by an abnormally high percentage of red blood cells (RBCs) and a higher than normal hematocrit, increasing blood viscosity.

The process of forming formed elements in the blood, primarily occurring in red bone marrow.

Cells that give rise to all types of blood cells.

Stem cells that give rise to red blood cells, platelets, and most white blood cells (excluding lymphocytes).

Stem cells from which lymphocytes develop.

A hormone that stimulates the production of red blood cell precursors.

Hemoglobin, found within red blood cells, is responsible for transporting oxygen and a small amount of carbon dioxide throughout the body.

Each hemoglobin molecule contains globin, a protein, and four heme groups. Each heme group binds to one iron atom (Fe2+), which can combine with one oxygen molecule.

Red blood cells have a lifespan of about 120 days due to wear and tear on their plasma membranes as they navigate blood capillaries. They cannot divide because they lack a nucleus.

Aged red blood cells are removed from circulation and destroyed by macrophages in the spleen and liver. The components are broken down and recycled.

The iron from heme is extracted and attached to transferrin, which carries it back to the red bone marrow for use in new hemoglobin synthesis.

The non-iron part of heme is transformed into biliverdin and then bilirubin, which is eventually passed to the liver. Bilirubin is further converted into urobilinogen in the intestines.

Some urobilinogen is reabsorbed into the bloodstream and excreted in urine as urobilin. Most is eliminated in feces as stercobilin, giving stools their brown color.

Erythropoiesis is the process of red blood cell production. It occurs in the red bone marrow and starts with a proerythroblast that undergoes multiple divisions to form a reticulocyte, which then matures into an erythrocyte in the bloodstream.

Indicates either a shortage of EPO or an inability of the red bone marrow to respond to EPO, resulting in decreased red blood cell production.

Genetically determined antigens found on the surface of red blood cells, responsible for classifying blood into different groups.

A blood group system based on the presence or absence of antigens A and B on red blood cells, resulting in four blood types: A, B, AB, and O.

Antibodies found in plasma that react with foreign antigens, causing agglutination (clumping) of red blood cells in incompatible blood transfusions.

Matching blood types for safe transfusions is crucial; incompatible blood leads to agglutination and hemolysis (red blood cell rupture) due to antigen-antibody reactions.

Another blood group system based on the presence or absence of the Rh antigen on red blood cells, classified as Rh+ (presence) or Rh- (absence).

Determining a person's ABO blood type by mixing blood with known antisera, causing agglutination (clumping) if the corresponding antigens are present.

A laboratory test that mixes donor blood with recipient blood to ensure compatibility, detecting any potential agglutination reactions before transfusion.

An increase in the number of white blood cells (WBCs) in the blood.

An abnormally low number of white blood cells (WBCs) in the blood.

A blood test that determines the percentage of each type of white blood cell in the blood.

A hormone that stimulates the production of platelets from myeloid stem cells.

The process where platelets clump together at a damaged blood vessel to stop bleeding.

The process of stopping bleeding.

The contraction of blood vessel smooth muscle to reduce blood flow after injury.

The process where activated platelets release chemicals from their vesicles to promote clotting.

White blood cells without cytoplasmic granules, including lymphocytes and monocytes, which differentiate into macrophages.

Large phagocytic cells that develop from monocytes, playing a crucial role in immune defense.

The process of white blood cells leaving the bloodstream to reach sites of inflammation or infection.

Proteins that enable white blood cells to stick to the inner lining of blood vessels, allowing them to move out.

A type of adhesion molecule that helps slow down neutrophils and cause them to roll along blood vessel walls.

Adhesion molecules that firmly attach neutrophils to blood vessel walls, helping them move through the capillary wall.

The process of engulfing and digesting foreign substances, typically performed by neutrophils and macrophages.

Blood protects against blood loss through clotting and fights infections by using white blood cells and specialized proteins.

Blood is thicker than water, meaning it flows more slowly. This is due to the presence of blood cells and proteins.

A thin layer of white blood cells (WBCs) and platelets found between the plasma and the red blood cells (RBCs) after blood is centrifuged.

The dissolved components of blood plasma, including proteins, nutrients, hormones, electrolytes, and waste products.

The method of obtaining blood samples by inserting a needle into a vein, typically the median cubital vein.

Withdrawal of blood from an artery, often used for specialized blood gas analysis.

Red blood cells are biconcave discs without nuclei that contain hemoglobin.

The reticulocyte count measures the rate of erythropoiesis by counting young, immature red blood cells in the blood.

White blood cells leaving the bloodstream to reach sites of inflammation or infection.

Insoluble protein fibers that create a network within a blood clot, trapping blood cells.

An enzyme complex essential for the conversion of prothrombin to thrombin, a crucial step in blood clotting.

The final stage of blood clotting, initiated by prothrombinase, leading to the formation of a fibrin clot.

A rapid blood clotting pathway initiated by tissue factor released from damaged tissue outside blood vessels.

A complex and slower blood clotting pathway activated by factors within the bloodstream.

The process of a fibrin clot tightening and consolidating, strengthening the blood clot.

An inactive enzyme incorporated into a blood clot, capable of dissolving the clot when activated.

Substances that inhibit blood clotting, preventing the formation of unwanted clots.